The aim of the proposed project is to elucidate the molecular mechanism of gene action in man ghrough a biochemical approach. The project consists of the following studies: a) Determination of specific amino acid substitutions of several phosphoglycerate kinase (PGK) variants and glucose 6-phosphate dehydrogenase (G6PD) variants. Since we determined the complete amino acid sequence of normal PGK and G6PD, the structural abnormalities can be correlated to their functional abnormalities, which induce hemolytic anemia and mental disorders in the subjects with the enzyme defects; b) The proposed study of the glucose-monophosphate shunt pathway activity and G6PD activity in permeabilized red cells may lead us to understand the unexplained "intra cellular restraint" of G6PD activity and the inconsistency between the degree of red cell G6PD deficiency and the severity of hemolysis in some G6PD variants; c) Determination of the complete amino acid sequence of normal human alpha1-antitrypsin (A1AT) will disclose the complete structures of normal and variant A1AT molecules; d) Study of the usual and atypical alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) at the protein level, and study of the organization of genes for ADH and ALDH. Molecular difference between the usual and atypical ADH2 isozymes, and evolutional relationships of these two enzymes and other isozymes (ADH1 and ADH3) will become apparent. The subunit structure of ALDH, and the genetic mechanism of missing ALDH-2 isozyme in the atypical subjects will be elucidated. These studies are of particular interest, since the frequency of atypical ADH and ALDH and sensitivity of alcohol intoxication and alcoholism are distinctively different between Caucasians and Orientals, and e) Study of the enzymatic and immunological properties of alpha-mannosidase from the mannosidosis patient may make clear the molecular region of this disorder, and the determination of the active site of pseudocholinesterase will disclose the exact molecular difference between the usual enzyme and atypical enzyme which is related to prolonged paralysis induced by suxamethionium.